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1、EIA 564 92 m 3234600 0503688 70T m EIA STANDARD ANSI/ EM-564-1992 APPROVED NaVmbW 12, 1992 Standard Test Method for Chemical Compatibility of Polycarbonate by Stress Crazing Evaluations DECEMBER 1992 ELECTRONIC INDUSTRIES ASSOCIATION ENGINEERING DEPARTMENT L Copyright Electronic Industries Alliance
2、Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- E I A 564 92 3234600 0503689 646 NOTICE EIA Engineering Standards and Publications are designed to
3、serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such S
4、tandards and Publications shall not in any respect preclude any member or nonmember of EIA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publications preclude their voluntary use by those other than EIA members
5、, whether the standard is to be used either domestically or internationally. Recommended Standards and Publications are adopted by IA in accordance with the American National Standards Institute (ANSI) patent poky. By such action, EIA does not assume any liability to any patent owner, nor does it as
6、sume any obligation whatever to parties adopting the Recommended Standard or Publication. This EIA Standard is considered to have Intemational Standardization implication, but the International Electrotechnical Commission activity has not progressed to the point where a valid comparison between the
7、EIA Standard and the IEC document can be made. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and heatth practices and to determine
8、the applicability of regulatory limitations before its use. Published by o ELECTRONIC INDUSTRIES ASSOCIATION 1992 Engineering Department 2001 Pennsylvania Ave. N.W., Washington, D.C. 26 PRICE: Please refer to the current Catalog Of EIA & JEDEC STANDARDS C ENGINEERING PUBLICATIONS or call Global Engi
9、neering Documents, USA and Canada (i-tlCWW7179) International (71 4-261-1 455) All rights reserved Printed in U.S.A. Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduct
10、ion or networking permitted without license from IHS -,-,- E I A 564 92 m 3234600 0503690 368 m a a PLEASE! DONT VIOLATE THE LAW! Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MD
11、TNo reproduction or networking permitted without license from IHS -,-,- E I A 5b4 92 = 3234b00 0503693 2T4 IA-564 Page 1 STANDARD TEST METHOD FOR CHEMICAL COMPATIBILITY OF POLYCARBONATE BY STRESS CRAZING EVALUATIONS (From Standards Proposai No. 2222, developed by the Packaging of Electronic Products
12、 for Shipment (PEPS) Committee.) 1. INTRODUCTION 1 . Chemical Environment Polycarbonate plastic is a strong engineering thermoplastic used in applications including the fabrication of sensitive electronic devices. In these applications close contact may exist with many substances such as anti-static
13、 films, greases, O-rings, detergents and other chemicals. These environments can cause crazing and cracking and thus field failure of the polycarbonate part. Chernical compatibility testing provides information on the extent to which chemical environments a f f e c t the allowable working stress of
14、polycarbonate thus establishing a method of limiting end-use failures. 0 1.2 End-Use Testing It should be understood that no short term test simulates all the environments of a particular plastic application. End-use testing of production parts is the only definitive method of establishing the suita
15、bility of a particular plastic part to a specific application. 2. SCOPE 2.1 Chemical Compatibility This method covers the determination of the chemical compatibility of polycarbonate resin with chemical substances that might contact the polycarbonate in its end use environment. The test measures the
16、 tendency for substances in contact with polycarbonate to cause stress cracking o r crazing of the polycarbonate resin. 2.2 Hazardous Materials This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated wi
17、th its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Empl
18、oyees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- E I A 564 72 3234b00 0503692 I130 W EIA-564 Page 2 3. SUMMARY OF METHOD The method consists of exposing annealed, transparent, injection molded polycarbon
19、ate test bars to the substance being evaluated for compatibility under standardized conditions of induced stress, temperature and time. After exposure, the test bars are evaluated for crazing and cracking. Substances that are compatible with polycarbonate resin produce crazing and cracking only at h
20、igh levels of induced stress and temperature. The information provided by the test is used to make decisions on how polycarbonate will perform when in contact with particular agents. 4. APPARATUS 4.1 Strain Jigs Four sets of strain jigs are required for each evaluation. The jigs are to be made of st
21、ainless steel with stainless steel tabs a t both ends capable of affixing the test bars to the jig so that intimate contact is maintained between the test bar and the jig along the entire length of the test bar. The stainless steel is to be of type 304 with a surface finish capable of providing inti
22、mate contact between the test bar and the jig. The jigs are to be curved so that affixing the plastic to the jig produces stresses in the plastic of 6.89 MPa (1000 psi), 11.71 MPa (1700 psi), 13.78 MPa (2000 psi), 17.23 Mpa (2500 psi) and 23.43 MPa (3400 psi). Figure 1 provides pictures of the jigs.
23、 Figure 2 provides a drawing of a jig with the appropriate curvatures calculated for a polycarbonate with a flexural modulus of 2,343 MPa (340,000 psi), as an example. The radius of curvature of the upper surface of the jig required to produce this stress can be calculated from the following equatio
24、n: ET T 2s 2 R = - - R = radius of curvatclre of upper surface of the jig (cm or in.). E = flexural modules of polycarbonate (MPa or psi). T = thickness of polycarbonate bar (cm or in.). S = stress produced in polycarbonate bar (MPa or psi). Copyright Electronic Industries Alliance Provided by IHS u
25、nder license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- EIA 564 92 D 3234600 0503693 077 D EI A-564 Page 3 4.2 Ovens Circulating air ovens capable of maintaining 49C (120“F
26、), 70C (158“F), 85“C, (185“F), and 121C (250F) each at +/- 1C (2F). 5. TEST SPECIMENS 5.1 Test specimens are transparent injection molded polycarbonate izod bars per ASTM D256. Clean handling techniques should be observed in the preparation and utilization of the polycarbonate specimens. 6. PROCEDUR
27、E 6.1 Annealing Anneal twenty polycarbonate bars by placing them on a flat sheet at 121C (250F) +/- 1C (2F) for 2 hours. Allow bars to cool at 23C (73F) +/-3“C (6F). 6.2 Mounting Mount the polycarbonate bars on the four sets of strain jigs assuring that intimate contact of the bars and jigs are main
28、tained along the entire length of the bars. 6.3 Exposing Expose the strained polycarbonate bars to the agent being evaluated for compatibility. Sheet materials or O-rings may be affixed to the bar with copper wire previously cleaned with isopropyl alcohol. The strained bars can be immersed in liquid
29、 agent. Alternately, clean cheese cloth saturated with the agent can be used to keep the top surface of the strained bars in contact with the liquid being evaluated. Grease materials can be wiped onto the surface of the bars. Tests of different agents must be isolated from each other to avoid cross
30、contamination. 6.4 Temperature Maintain one s e t of exposed and strained polycarbonate bars at each temperature being evaluated, namely 23C (73“F),49“C (1 20“F), 70C (158F) and 85C (1 &OF) each +/- 1C (2F) for five days. Reapply agents that volatilize in order to maintain continued chemical exposur
31、e. 6.5 Duration After five days remove the bars from the jigs, wipe clean and inspect visually for crazes and cracks. Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduc
32、tion or networking permitted without license from IHS -,-,- E I A 569 72 3234600 0503674 TO3 W EIA-564 Page 4 7. EVALUATION OF TEST SPECIMENS 7.1 Evaluate each bar according to the following craze rating scheme (see Figure 3 for pictures of crazes) : RATING CRAZE DESCRIPTION o None - No crazing or c
33、racking. 1 2 Very Slightly Crazed - Minute edge crazes on surface of bar, barely visible. Slightly Crazed - Small crazes visible on both edge and top of bar. 3 Crazed - Thin long crazes, very noticeable. 4 Severely Crazed - Thick cracks in bar. 5 Broken - Bar split into more than one piece. 7.2 Cont
34、rol samples of the polycarbonate shall be evaluated with no chemical exposure but with identical strains, temperatures and times. This will establish the independent performance of the annealed polycarbonate and assist in deducing the affect of the chemical environment in question. 8. REPORT 8.1 The
35、 report should provide: O Complete identification of the polycarbonate. Complete identification of the agent evaluated for compatibility. O The individual craze ratings a t each of the twenty environments oi stress anc temperature evaluated. O The maximum stress that the exposed polycarbonate surviv
36、ed without crazing (crazed rating equals zero) at each temperature evaluated. 9. REFERENCES - ASTM F791-82 “Standard Practice for Stress Crazing of Transparent Plastics“ Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Berni
37、e Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- EIA 564 92 3234600 O503695 9 4 T Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2
38、007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- E I A 5b4 92 3234600 0503696 B6 EIA-564 Page6 POLYCARBONATE BAR 0 / M - 0 STEEL JIG I RAD I US Figure 2 Radius of Curvature of Upper Surface of Jig Stress Produced in a Polycarbonate of 2343 MPa (340,Ooo psi) cm M
39、Pa Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,- E I A 5b4 72 m 3234b00 O503677 712 m Copyright Electronic Industries Alliance Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 21:51:28 MDTNo reproduction or networking permitted without license from IHS -,-,-
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